[java] How can I get Android Wifi Scan Results into a list?

I know how to get a <List> of Android Wifi Scans but I can not figure out the best way to make a list adapter out of them. I would like to just bind SSID and BSSID from a <List> of scans to text1 and text2.

Samples of what I have been doing

wifi.startScan();
        // get list of the results in object format ( like an array )
        List<ScanResult> results = wifi.getScanResults();`

        // loop that goes through list
        for (ScanResult result : results) {
            Toast.makeText(this, result.SSID + " " + result.level,
                    Toast.LENGTH_SHORT).show();

And:

private void fillDataFromDb() {
        Cursor scanCursor = Db.fetchAllScans();
        startManagingCursor(scanCursor);`

        // Create an array to specify the fields we want to display in the list
        // (only TITLE)
        String[] from = new String[] { WifiDbAdapter.KEY_BSSID,
                WifiDbAdapter.KEY_SSID };

        // and an array of the fields we want to bind those fields to (in this
        // case just text1)
        int[] to = new int[] { R.id.text1, R.id.text2 };

        // Now create a simple cursor adapter and set it to display
        SimpleCursorAdapter scansdb = new SimpleCursorAdapter(this,
                R.layout.scan_row, scanCursor, from, to);
        setListAdapter(scansdb);
    }

This question is related to java android listview android-wifi

The answer is


In addition for the accepted answer you'll need the following permissions into your AndroidManifest to get it working:

 <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
 <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /> 

Wrap an ArrayAdapter around your List<ScanResult>. Override getView() to populate your rows with the ScanResult data. Here is a free excerpt from one of my books that covers how to create custom ArrayAdapters like this.


refer below link for getting ScanResult with redundant ssid removed from the list

duplicate SSID in scanning wifi result


Find a complete working example below:

The code by @Android is very good but has few issues, namely:

  1. Populating to ListView code needs to be moved to onReceive of BroadCastReceiver where only the result will be available. In the case result is obtained at 2nd attempt.
  2. BroadCastReceiver needs to be unregistered after the results are obtained.
  3. size = size -1 seems unnecessary.

Find below the modified code of @Android as a working example:

WifiScanner.java which is the Main Activity

package com.arjunandroid.wifiscanner;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class WifiScanner extends Activity implements View.OnClickListener{


    WifiManager wifi;
    ListView lv;
    Button buttonScan;
    int size = 0;
    List<ScanResult> results;

    String ITEM_KEY = "key";
    ArrayList<String> arraylist = new ArrayList<>();
    ArrayAdapter adapter;

    /* Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        getActionBar().setTitle("Widhwan Setup Wizard");

        setContentView(R.layout.activity_wifi_scanner);

        buttonScan = (Button) findViewById(R.id.scan);
        buttonScan.setOnClickListener(this);
        lv = (ListView)findViewById(R.id.wifilist);


        wifi = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        if (wifi.isWifiEnabled() == false)
        {
            Toast.makeText(getApplicationContext(), "wifi is disabled..making it enabled", Toast.LENGTH_LONG).show();
            wifi.setWifiEnabled(true);
        }
        this.adapter =  new ArrayAdapter<>(this,android.R.layout.simple_list_item_1,arraylist);
        lv.setAdapter(this.adapter);

        scanWifiNetworks();
    }

    public void onClick(View view)
    {
        scanWifiNetworks();
    }

    private void scanWifiNetworks(){

        arraylist.clear();
        registerReceiver(wifi_receiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));

        wifi.startScan();

        Log.d("WifScanner", "scanWifiNetworks");

        Toast.makeText(this, "Scanning....", Toast.LENGTH_SHORT).show();

    }

    BroadcastReceiver wifi_receiver= new BroadcastReceiver()
    {

        @Override
        public void onReceive(Context c, Intent intent)
        {
            Log.d("WifScanner", "onReceive");
            results = wifi.getScanResults();
            size = results.size();
            unregisterReceiver(this);

            try
            {
                while (size >= 0)
                {
                    size--;
                    arraylist.add(results.get(size).SSID);
                    adapter.notifyDataSetChanged();
                }
            }
            catch (Exception e)
            {
                Log.w("WifScanner", "Exception: "+e);

            }


        }
    };

}

activity_wifi_scanner.xml which is the layout file for the Activity

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:padding="10dp"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:id="@+id/wifilist"
        android:layout_width="match_parent"
        android:layout_height="312dp"
        android:layout_weight="0.97" />


    <Button
        android:id="@+id/scan"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_gravity="bottom"
        android:layout_margin="15dp"
        android:background="@android:color/holo_green_light"
        android:text="Scan Again" />
</LinearLayout>

Also as mentioned above, do not forget to add Wifi permissions in the AndroidManifest.xml

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /> 

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